Anna is a secondary character who serves as Aiden's ally in solving the murder. She remains in the same body throughout the events and helps gather information, leveraging her ability to go unnoticed.

The Plague Doctor acts as a guide and confidante for Aiden. He is a mysterious, partially omniscient figure who understands the rules of the game and aids Aiden while being bound by these rules himself.

Evelyn is the central figure around whom the plot revolves, as the story seeks to identify her killer. Her character involves elements of disguise and deception, which complicates the plot.